def is_A(n):
    if n<2:
        return n+n
    else:
        return n
print(is_A(100))
print(is_A(-100))
def is_prime(n):
    if n < 2:
        return False
    for i in range(2, int(n**0.5)+1):
        if n % i == 0:
            return False
    return True

is_prime(11) # True
is_prime(10) # False
print(is_prime(11))
print(is_prime(10))

def factorial(n):
    if n == 0:
        return 1
    else:
        return n * factorial(n-1)

print(factorial(5)) # 120
print(factorial(10))